Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B5/00—Measuring arrangements characterised by the use of mechanical techniques
  • G01B5/24—Measuring arrangements characterised by the use of mechanical techniques for measuring angles or tapers; for testing the alignment of axes
  • G01B5/25—Measuring arrangements characterised by the use of mechanical techniques for measuring angles or tapers; for testing the alignment of axes for testing the alignment of axes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B21—MECHANICAL METAL-WORKING WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D—WORKING OR PROCESSING OF SHEET METAL OR METAL TUBES, RODS OR PROFILES WITHOUT ESSENTIALLY REMOVING MATERIAL; PUNCHING METAL
  • B21D3/00—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts
  • B21D3/10—Straightening or restoring form of metal rods, metal tubes, metal profiles, or specific articles made therefrom, whether or not in combination with sheet metal parts between rams and anvils or abutments
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
  • G01B7/28—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring contours or curvatures
  • G01B7/281—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring contours or curvatures for measuring contour or curvature along an axis, e.g. axial curvature of a pipeline or along a series of feeder rollers
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C17/00—Monitoring; Testing ; Maintaining
  • G21C17/06—Devices or arrangements for monitoring or testing fuel or fuel elements outside the reactor core, e.g. for burn-up, for contamination
• • G—PHYSICS
  • G21—NUCLEAR PHYSICS; NUCLEAR ENGINEERING
  • G21C—NUCLEAR REACTORS
  • G21C19/00—Arrangements for treating, for handling, or for facilitating the handling of, fuel or other materials which are used within the reactor, e.g. within its pressure vessel
  • G21C19/02—Details of handling arrangements
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
  • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
  • Y02E30/00—Energy generation of nuclear origin
  • Y02E30/30—Nuclear fission reactors

Definitions

• the present invention relates to a device for measuring and correcting a parallelism defect of a nuclear fuel rod, more particularly a parallelism defect at the end provided with the top plug.
• a nuclear fuel assembly is comprised of a plurality of nuclear fuel rods arranged parallel to one another so that the assembly is substantially square in cross-section.
• Each pencil comprises a sheath, which is a very long tube of small diameter, closed at its lower end and in which are stacked cylindrical nuclear fuel pellets circular section. When the number of pellets required has been introduced into the sheath, its open end is closed by a plug, said upper cap. This assembly formed by the sheath, the lower and upper caps and the pellets constitutes the pencil.
• the assembly comprises a lower end receiving the end of each pencil provided with the lower plug and an upper end receiving the end of each pencil provided with the top plug.
• the lower end and the upper end are provided with housing receiving individually each end of pencil.
• the upper and lower ends are connected by rigid rods so as to form a rigid frame.
• the parallelism of the end cap end is sufficient.
• a parallelism defect appears at the end of the upper plug when the upper plug is welded to the welded lower plug or TSBI tube which corresponds to the sheath provided with the lower plug.
• Such a defect can also appear due to an accidental deformation of the end of the top plug during the handling of the rods. Other causes may be the cause of this lack of parallelism.
• JP 10 123283 discloses a device for measuring the parallelism defect of a pencil end comprising a probe, the pencil being rotated.
• This document also describes a device for measuring the parallelism defect comprising at least two linear sensor probes orthogonal to the axis of the pencil, for measuring the axis of the top plug, the use of at least two probes to avoid to rotate the pencil. This measurement makes it possible to measure the difference between the axis of the upper plug and that of the pencil. These measuring devices do not make it possible to correct the lack of parallelism.
• a device for measuring a parallelism defect and correction of this defect including means for measuring this defect, and means for correcting this defect, the measuring and correction means being arranged so that they allow a real-time measurement of the defect, more particularly its evolution during its correction.
• the device also comprises means for positioning said device on the pencil and cooperating with a rack on which the pencil is stored.
• this device avoids excessively correcting the defect and causing another to appear. It is easily transportable and manipulable.
• this device is portable, which avoids moving the rods, since the measuring and correction device is moved.
• the present invention therefore mainly relates to a device for measuring and correcting a parallelism defect of a top plug end of a nuclear fuel rod having means for measuring a parallelism defect and correction means said fault, said correction means being disposed opposite the measuring means with respect to the location of the rod, to allow a measurement of the parallelism defect during the correction of said defect.
• the measuring means comprise, for example a feeler intended to come into contact with the periphery of the top end cap of the rod, said probe being movable along an axis transverse to the axis of the location of the pencil.
• the correction means may comprise, for their part, a pusher intended to come into contact with the periphery of the upper end of the pencil end, said pusher being movable along an axis transverse to the axis of the location of the pencil. pencil, the axis of movement of the pusher and the axis of movement of the probe being contained in a plane containing the axis of movement of the pencil.
• the device according to the invention may also comprise means for holding the pencil while allowing to rotate said pencil about its longitudinal axis, said holding means having a lower jaw and an upper jaw for gripping the pencil, the lower jaw forming a reference for measuring the lack of parallelism.
• the jaws are friction-reducing material, for example ertalyte ®, which ensures the maintenance of the pencil without preventing the rotation of the pencil.
• the upper jaw is advantageously articulated about an axis parallel to the axis of the pencil location, and locking means in the lower and upper jaw holding position being provided, which facilitates the introduction of the pencil. .
• the pusher is, for example mounted on one end of a threaded rod mounted a threaded hole made at the end of an arm, said rod having a handle at the end opposite to that on which is fixed the pusher, allowing manually move the pusher.
• a stop is advantageously fixed on the rod to which is fixed the pusher so as to limit the movement of the pusher towards the probe, which avoids excessive deformation of the upper end cap.
• the device according to the invention may also comprise a ring between the holding means and the correction means, of axis parallel to the axis of the pencil location, said ring being intended to be crossed by the pencil and intended to take up the deformation efforts applied to the pencil.
• the device according to the invention may also comprise an axial abutment for the pencil, this abutment being disposed transversely with respect to the axis of the pencil location, downstream of the measuring means in the direction of insertion of the pencil into the pencil. device. The positioning of the pencil is then easy.
• the device may also comprise means for positioning said device relative to the pencil, said positioning means being intended to cooperate with the pencil and a rack on which the pencil is stored, said positioning means comprising two pieces in the form of a horseshoe whose inner bottoms are intended to rest on an upper zone of the periphery of the pencil, the two parts being separated from each other by a given distance, so as to allow the overlap of the rack on which the end rests upper cap of the pencil, the support having a thickness substantially equal to the distance between the two horseshoe parts.
• the measuring means and the correction means are carried by a platform connected to the positioning means by two parallel beams intended to follow the pencil.
• the locking means of the lower and upper jaws are for example formed by a threaded rod mounted articulated about an axis parallel to the axis of the pencil location, on a side opposite to that on which the upper jaw is hinged, and a knob screwed onto the threaded rod, the jaw having a notch to receive the threaded rod, the button being disposed opposite the lower jaw relative to the upper jaw when the rod is in the notch, to ensure the locking of the lower and upper jaws.
• These locking means are of simple construction and provide fast and efficient locking.
• the present invention also relates to a method for measuring and correcting a parallelism defect implementing the measuring and correction device according to the invention, comprising the following steps: a) placing the device on the pencil at the level of the upper plug end, b) displacement of the rod along its axis to position it between the measuring means and the correction means, c) locking of the pencil holding means, d) pencil rotation and detection the lack of parallelism, e) determination of the correction to be made, f) orientation of this defect towards the correction means, g) correction of this defect by applying a deformation force applied by the correction means, and simultaneous control with the information provided by the measuring means, h) checking the parallelism defect by checking that it is less than one given threshold value, i) repetition of steps d) to h) if the value of the parallelism defect is greater than the given threshold value.
• the pencil is manually rotated, making the process simple and the device even less cumbersome and more robust.
• FIG. 1 is a three-quarter perspective view of an exemplary embodiment of a measuring and correction device according to the present invention
• FIGS. 2A to 21 are views of the device of FIG. 1 during the various steps of measuring and correcting the parallelism defect of a nuclear fuel rod
• FIGS. 3A and 3B are diagrammatic representations of the dial of the measurement means when measuring a parallelism defect.
• FIG. 1 and FIGS. 2A to 21 ' an exemplary embodiment of a device 2 for measuring and correcting a nuclear fuel rod, designated device in the following description, can be seen.
• the device 2 is intended to be positioned on a rack 4, visible in Figure 2A, on which are stored the rods 6.
• the rack 4 comprises two parallel supports, at a distance from one another and each supporting a longitudinal end of a pencil. Each support has notches 10 forming housings for a longitudinal end of a pencil. In FIG. 2, the support 8.1 of the upper cap ends 6.1 of the rods 6 can be seen.
• the rods 6 are received in the notches 10 sufficiently upstream of the upper plug 12, so that the plug and a portion of the sheath are cantilevered on the support.
• the device 2 comprises means 14 for positioning the device on the rack 4, more particularly on the support 8.1.
• the positioning means 14 comprise two pieces 16.1, 16.2 in the form of horseshoes rigidly held in parallel manner by rods 18.
• the width of the air gap of the parts 16.1, 16.2 is substantially equal to the diameter of the sheath of a pencil to allow the parts 16.1, 16.2 to ride a pencil.
• the bottom of the air gaps have a radius of curvature substantially equal to that of the sheath of the pencil.
• the distance separating the two parts 16.1, 16.2 is substantially equal to the thickness of the support 8.1, so that the parts can be arranged on either side of the support, and the device is fixedly positioned relative to the pencil. because of the small clearance between the faces of the support and the faces of the parts.
• the device comprises means for measuring a parallelism defect 20 and correction means 22 for this lack of parallelism. These means 20, 22 are arranged at a first longitudinal end 24.1 of a mast 26, which is fixed by a second longitudinal end 24.2 to the positioning means 14.
• the mast 26 is formed by two parallel beams 26 connected to one another at their second longitudinal ends on the side of the positioning means 14, by a horseshoe piece 28.
• the spacing of the two beams 26 is identical to the air gap of the parts 16.1, 16.2.
• the measuring and correction means 22 are arranged on a platform 30, on which also provided retaining means 32 of a pencil.
• the holding means 32 are arranged between the positioning means 14 and the measuring and correction means.
• a longitudinal location 31 of axis X of the rod (see Figure 2E) is delimited between the beams, and in the platform 30 between the holding means 32 and a bottom 33 forming a stop, the measuring means 20 and correction 22 bordering this location 31.
• the holding means 32 are intended to grip sufficiently the pencil to serve as a reference to the measurement, while allowing the rotation of the pencil around its axis.
• the holding means comprise a V-shaped lower jaw 34 intended to support the rod, and a V-shaped upper jaw 36 intended to come over the rod to prevent its displacement in a plane orthogonal to the axis of the rod. pencil.
• the lower jaw 34 forms the reference for the measurement.
• the jaws 34, 36 are made of a material allowing the sliding of the pencil, which makes it possible not to hinder the rotation. They are made, for example ertalyte®.
• the upper jaw 36 is mounted on a plate 37, itself articulated on the platform 30 about an axis parallel to the axis of the pencil, which opens the holding means and facilitate the placement of the pencil.
• the locking system 38 comprises a rod 40 mounted on the platform 30, articulated in rotation on it. ci about an axis parallel to the axis X, the opposite side to that of the axis of articulation of the upper jaw 36.
• the rod 40 has a threaded end 40.1 on which is screwed a button 44.
• the plate 37 of the upper jaw 36 has a notch 45 on the opposite side to its axis of articulation intended to receive the threaded rod 40, the button 44 being arranged on the outside so as to exert a clamping force on the plate to lock the jaw upper 36 facing the lower jaw 34, in the position shown in Figure 2C.
• any other system to allow the spacing and the approximation of the lower jaw 34 and upper 36 may be provided.
• the platform comprises, downstream, holding means, a ring 46 intended to take up all of the deformation force necessary for the correction.
• the means for measuring a parallelism defect 20 are arranged at the free end of the platform 30 so as to be located below the pencil, as can be seen in FIG. 2A.
• the measuring means 20 are of the mechanical push type, formed by a feeler 47 able to slide in a bore 48 made in the platform 30.
• the bore 48 is vertical.
• the probe 47 is intended to come into contact with its free end
• the probe 47 is connected to a mechanical movement, to convert the longitudinal displacement of the probe 47 into a parallelism fault value.
• This value is then displayed on a dial 50 to be visible to the operator.
• a dial 50 In the example shown, it is a needle dial.
• the mechanical movement is composed of gears, rods and toothed sectors to allow this conversion.
• Capacitive sensors can also be used instead of a mechanical sensor.
• the measuring means form a comparator for comparing the shape of the upper end cap of the pencil with respect to a reference which is given by the lower jaw 34, and to display the difference with respect to this reference.
• the probe 47 is biased upwards by an elastic means ensuring continuous contact of the probe on the pencil and allowing continuous measurement.
• the correction means 22 are intended to apply a force on the upper cap end so as to eliminate the defect, or at least reduce it so that it is within acceptable tolerances.
• the correction means 22 are arranged diametrically opposite the probe relative to the pencil so that, simultaneously with the correction of the parallelism defect, the probe of the measuring means can make it possible to continuously know the evolution of the defect.
• the axis of displacement of the pusher 52 and that of the probe 47 are not in the same plane orthogonal to the axis of the pencil. But it is understood that this configuration is in no way limiting.
• the position of the pusher depends on the effort to be transmitted in pencil. Moreover, in the example shown, it is arranged so that there is no interaction with the stop 33.
• the correction means 22 comprise a vertically movable pusher 52 intended to come into contact with the upper plug end in order to apply a deformation force thereto.
• the pusher 52 is mounted for example at the end of a threaded rod 54 mounted in a tapped hole 56 formed at the end of an arm 58.
• the 58 is arranged so that the probe 52 is at the right of the upper end cap of the pencil.
• the rod 54 comprises a handle 60 at its end opposite that carrying the pusher 52, to facilitate the rotation of the threaded rod 54 and the vertical displacement of the pusher 52.
• This screw-nut system facilitates the vertical displacement of the pusher 52.
• the pusher 52 is rotatably mounted on the threaded rod 54.
• This embodiment is particularly simple and robust, in addition it is lightweight and compact, which makes the device easily portable.
• the pusher 52 has a V-shaped groove intended to be applied to the pencil.
• the effort is thus better distributed on two generatrices of the pencil.
• the presence of this groove makes it possible to improve the retention of the pencil during the application of the deformation force, while avoiding deforming the surface of the pencil.
• stop means 62 are provided to prevent excessive vertical displacement of the pusher 52 towards the probe, preventing excessive deformation of the upper end cap.
• These vertical abutment means 62 are formed, in the example shown, by a ring fixed on the rod 54, on the side of the arm 58 opposite the pusher 52.
• the ring 62 is fixed at a determined position avoiding excessive deformation.
• the ring 62 abuts against the arm 58 to stop the movement of the pusher 52 towards the probe, and therefore an additional deformation of the pencil.
• a device according to the present invention has a length of 308 mm, a height of 175 mm and a width of 71 mm, which makes it easily manipulated by a single operator.
• the pencils are arranged on the rack 4.
• the device 2 is brought vertically and is placed astride a pencil 6 and on the support 8.
• the parts 16.1, 16.2 are arranged on either side of the support 8, and the beams are arranged on both sides. other pencil ( Figure 2A).
• the device 2 then rests on the pencil by the bottom of the air gaps parts 16.1, 16.2, as can be seen in Figure 2B.
• the upper cap end is between the two beams ( Figures 2B and 2B ').
• the pencil is moved axially in order to arrange the upper end cap on the probe.
• the pencil slides on the lower jaw 34, in the ring 46, until its free end bears against the bottom 33.
• the probe 47 is held in a low position to avoid interference between the pen and the probe.
• the probe is released and bears against the upper end cap ( Figures 2C and 2C).
• the operator can determine what deformation he must apply to the pencil using the pusher to correct the parallelism of the pencil and make it acceptable.
• the deformation is determined experimentally.
• the correction determined is 2.3 mm; if P ⁇ 0.35 mm, the determined correction is 2.4 mm. It is necessary, for example, to apply a force corresponding to the force required to be applied to a cylindrical Zircaloy beam 5 mm in diameter and 40 mm in length, embedded at one end and free from the other, to deform the free end of 2.5. mm. The operator then calculates the correction to be applied, i.e. the value to be read on the comparator when the defect is oriented upwards and that a force is applied with the pusher.
• This value DFH aat dye d is equal to the sum of the determined correction, and the measured DFH default.
• the operator positions the pen so that the fault is pointing upwards. He then puts the pusher 52 in support on the pencil, the pencil being received in the V-shaped groove, as can be seen in FIG. 2G, no force is yet applied to the upper cap end.
• the handle is rotated so that the pusher applies a deformation force to the upper cap end towards the probe to modify the defect, as shown in Figure 2H, it can be seen that the probe 47 is depressed.
• the force applied is such that it causes a displacement of the needle in the opposite direction to the DF value of the defect, plus an additional displacement of value given to actually cause a plastic deformation of the pencil.
• the operator moves the pen to read on the comparator the value DFH aa to reach determined above.
• the operator permanently visualizes the deformation which he applies to the pencil thanks to the probe which continues to measure the position of the upper end cap. This visualization makes it possible to avoid applying excessive force to the pencil. The correction process is therefore faster, since it is better controlled.
• the operator lifts the pusher 52 (FIGS. 21 and 21 ') and verifies the beat of the upper cap end.
• the pusher is returned to the high position.
• the operator turns the pencil again, and determines the beat. It measures again the fault when it is pointing upwards and the fault is pointing downwards.
• this threshold may be equal to 0.25, the beat must not, in this case, exceed 0.5. If, during the check, the parallelism fault is greater than the threshold, the operator repeats the previous steps of correcting it by applying a deformation force on the upper end cap and checking the parallelism defect.
• This device has the advantage of allowing correction of the parallelism of the upper end of a pencil while allowing to continuously quantify the deformation performed, since the measuring means 20 remain active during the correction step.
• this device is compact, easily manipulated by a single operator and combines the measurement of the defect and the correction of this defect. he can be set up on each pencil with minimal manipulation of the pencils, only a longitudinal displacement of a few centimeters and rotational displacements of the rods around their axis are required.
• this device advantageously uses the rack as a support. It does not require an additional support element.
• the probe and the pusher have vertical movements, but it is understood that a device whose probe and the pusher having displacements along axes inclined with respect to the vertical direction does not go beyond the scope of the In this case, it will be provided that the pusher and the measuring system are facing each other.

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• Physics & Mathematics (AREA)
• Engineering & Computer Science (AREA)
• General Physics & Mathematics (AREA)
• Plasma & Fusion (AREA)
• General Engineering & Computer Science (AREA)
• High Energy & Nuclear Physics (AREA)
• Mechanical Engineering (AREA)
• Monitoring And Testing Of Nuclear Reactors (AREA)
• A Measuring Device Byusing Mechanical Method (AREA)

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• 2008
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• 2009
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  • 2009-09-14 CN CN2009801411709A patent/CN102187175B/zh active Active
  • 2009-09-14 WO PCT/EP2009/061839 patent/WO2010029166A1/fr active Application Filing
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